Just use my repo for referring your leetcode solution.
Given the root of a binary tree, invert the tree, and return its root.
Example 1:
Input: root = [4,2,7,1,3,6,9]
Output: [4,7,2,9,6,3,1]
Example 2:
Input: root = [2,1,3]
Output: [2,3,1]
Example 3:
Input: root = []
Output: []
Submission:
Given the root of a binary tree, return its maximum depth.
A binary tree's maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.
Example 1: Input: root = [3,9,20,null,null,15,7] Output: 3
Example 2: Input: root = [1,null,2] Output: 2
Approach: Using recursive DFS to calculate depth of left and right subtrees, then return max + 1. Runtime: 0 ms (Beats 100.00%)
Given the roots of two binary trees p and q, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.
Example 1: Input: p = [1,2,3], q = [1,2,3] Output: true
Example 2: Input: p = [1,2], q = [1,null,2] Output: false
Approach: Three recursive checks - both null (true), one null (false), values differ (false). Then recursively verify left AND right subtrees match. Runtime: 0 ms (Beats 100.00%)